Features related to overrun cushioned carriage return mechanism



y 1957 H. c. YAEGER 2,797,789

FEATURES RELATED TO OVERRUN CUSHIONED CARRIAGE RETURN MECHANISM 2 Sheets-Sheet 1 Filed Dec. 21, 1953 INVENTOR.

HARRY C. VAEGER BY 2& 07%;

ATTORNEY 2 SheetsSheet 2 A T TORNE) IN VEN TOR. HARRY C. X45651? July 2, 1957 H. c. YAEGER.

FEATURES RELATED TO OVERRUN CUSHIONED CARRIAGE RETURN MECHANISM Filed Dec. 21, 1955 2,797,789 Patented July 2, 1957 FEATURES RELATED TO OVERRUN CUSHIONED CARRIAGE RETURN MECHANISM Harry C. Yaeger, West Hartford, Conn., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application December 21, 1953, Serial No. 339,518

8 Claims. (Cl. 197-66) This invention relates to recording machines in general, such as typewriters, embodying a carriage adapted to step-feed to a successive recording position incidental to each recording made, and particularly with reference to such machines relates to mechanism to terminate the return of the carriage quietly by permitting it to overrun idly an indefinite distance past the intended initial recording position, the machine including provision to cause the carriage thereafter to settle in the correct initial recording position.

It is a general object of the invention to provide an improved mechanism of the kind hereinabove stated.

It is also an object of the invention to provide in conjunction with the stated species of mechanism efficiently active means to decelerate the overrunning carriage rapidly, but without objectionable shock and noise, so that recording or typing can be resumed with the least loss of time.

In mechanisms of the kind stated there elapses essentially an interval of time while the carriage overtravels and until it settles in the initial recording position. During such interval an operator may inadvertently and prematurely depress a control key for the recording mechanism. Accordingly, it is a further object of the invention to provide in combination with the stated mechanism simple and eificient means to suppress the institution of recording .or typing operations while the carriage is overrunning and until it settles in the initial recording position.

It is also an important object of the invention to provide a power returning means for the carriage efficiently coordinated with other devices to attain the general objects noted herein.

A still further object of the invention is to provide efficient means whereby to suppress recording operations not only during the stated overrun of the carriage and the ensuing automatic advance, but also while the carriage is being returned.

Still other objects of the invention will be apparent upon consideration of detailed description of an exemplary embodyment thereof which follows, as such description is read in the lightof the above stated general objects and the accompanying drawings.

Having now specific reference to the drawings,

Figure 1 is a fractional front perspective looking at an angle downwardly and rightwardly on a right-hand portion of a typewriter which embodies the invention,

Figure 2 is a fractional plan view of a mechanism that serves to block typing instrumentalities againstoperation, said mechanism being in operated, efiective position,

Figure 3 shows a portion of the mechanism seen'in Figure 2, in normal position,

Figure 4 is a left-hand front perspective view, illustrating a portion of a paper-supporting stepping carriage, along with connections to an escapement wheel. At

the lower end of the view a group of parts related to the escapement wheel are shown in exploded aspect,

Figure 5 is a fractional rear elevation of the carriage return control mechanism in a normal state,

Figure 6 is also a rear elevation and shows certain parts of the mechanism seen in Figure 5 in operated position, and finally,

Figure 7 is a rear elevation showing the carriage return control mechanism in a return shut-off condition.

The machine illustrated embodies typing instrumentalities such as disclosed in the patent to Yaeger No. 2,254,764, dated September 2, 1941. Referring now to Figure 1, such typing instrumentalities comprise a system of type actions, each of which comprises a pivoted type bar 12 operable by a lever 13 through a link 14. The type action shown is a central one of a usual system embodying many levers 13 individually in control of type bars 12 which at operation type at a common point. Each lever 13 is power operable by an actuator 16 through a rolling lever association at 17. All the actuators 16 are normally held raised off a toothed power roll 20 by individual springs 21. Said toothed power roll 20 is constantly turning in the direction of the arrow while the machine is in use, and when a type key lever 22 is depressed a hook element 23 thereon will lower the actuator 16 related thereto for reception of motion from the toothed roll 20 thereby to effect the operation of the type bar 12 against .a platen 26 seen in Figure 4. The various key levers '22 are pivoted on a common fulcrum rod 24 which is supported in a crossbar 25 of a machine framework. Said platen 26 is part of a usual carriage assembly comprising a rail 27 and two upright ends 28. The carriage, by association of said rail 27 upon a usual run-way 31 is guided to travel laterally thereon, said run-way being part of said framework of the machine which moreover includes a right side wall 32 and also a left side wall, not shown.

As is usual in typewriting machines, the carriage is constantly urged in carriage feed direction by a feed spring 29, indicated in Figure 4. However, an escapement dog 35 associated with an escapement wheel 36 normally holds the carriage against advance movement by said feed spring 29, said escapement wheel 36 forming with a shaft 37 and a pinion 38 an assembly which is rotatable on the framework of the machine through the geared association of said pinion with a rack 40 on the carriage, the framework of the machine including a bracket 39 turnably supporting the lower end of the shaft 37, and also having thereon a pivot pin 49 for the dog 35. At operation of any of the type actions, by means not shown, the escapement dog 35 is momentarily operated to allow a one-tooth advance of the escapement wheel, the carriage feeding therefore one letter space or step under the urge of the feed spring 29.

The carriage 27, 28 is preferably returnable under the power of a motor, not shown. Said motor by means of a belt drive indicated at 41, in Figure 5, drives a spindle 42 continuously whenever the machine is in use. The spindle 42 is accommodated in a bushing 43 which extends from a flange 44 having support on the side wall 32 of the machine. Upon said bushing 43 there is turnably mounted a pulley 45 which has wound thereupon and leading to the carriage a carriage return drawband 46. Said drawband extends from said pulley 45 over guide sheaves 47 to a pulley 48 on the left carriage end 28 which is limitedly operable, in a usual manner, to effect the actuation of a line spacing mechanism, not shown. Within a barrel 50 provided on the bushing 43, there is a clock spring, not shown, urging the pulley 45 lightly to keep the drawband 46 taut. One flange of the drawband pulley 45 constitutes a clutch disk .51

and rotatable with such disk, axially spaced therefrom, there is another clutch disk 53, such latter clutch disk being slidably carried upon pins 54 extending from the disk 51 parallel to the spindle 42. Sandwiched normally loosely between the disks 51 and 53 there is a driver clutch disk 55 which is splinedly carried upon the spindle 42. While the machine is in use, normally, the driver disk 55 rotates idly between the disks 51 and 53, springs 56 on the studs 54 serving to spread the clutch disk 53 from the disk 51.

The clutch, constituted by the stated clutch disks 51, 53, 55, is closea-ble at operation of a carriage return key 57 in a manner to be presently described. The key 57 is part of a lever having a pin 60. When the; key

57 is depressed, said pin 60 operates a lever 61 similar to the type key lever 22 to draw down by means of a hook element 63, the rear end of an actuator 64.

This brings such actuator 64 into motion receiving relation with the constantly turning toothed shaft 20, wherefore said actuator receives a power motion towards the front of the machine. A pendant arm 65 to which the actuator is linked is thus operated toward the front of the machine, and in turn operates a link 66. The latter is operative on a bell crank 67 having pivotal support on the machine side wall 32 and being under the bias of a spring 69 to bias the parts 64 to 68 and 70 towards their normal positions. The bell crank 67 at actuation of the actuator 64, through a link 63, displaces clockwise, as viewed from the front of the machine, a lever 70 pivoted on a stationary axis 72 and having a roll 71 thereon. The lever 70, by the medium of the roll 71, is in control of a clutch closing structure 73 having a pivotaxis at 75. Said structure 73 under the urge of a spring 74 occupies normally the position seen in Figures 1 and 5, and has thereon an upreaching arm 77 adjustably secured thereto. Specifically, said arm 77 has pivotal association with the structure 73 at 73 and is swingably adjustable thereon about the point 78 by a settable and lockable eccentric device indicated at 80, Figure 5. At downward actuation of the lever 70 the roll 71 wipes down along a cam face 81 on the arm 77 to the position seen in Figure 6, causing the structure 73 to swing and squeeze the clutch elements 53, 55, 51 into closed clutch relation. The pulley 45 commences thus to be power-turned drawing the band 46, first to operate the line-spacing mechanism, and then to draw the carriage in return direction.

The actuator 64 in being power operated becomes disassociated from the power roll in a well-known manner but the clutch obviously must remain closed to the conclusion of the carriage return run. To this end the lever 70 carries fast thereon an arm 83 which by a lug thereon, at operation of the lever 70 will be caught and held by a latch 84. The clutch then remains closed pending the return travel of the carriage under power to a certain position when a carriage return shut-off element 87 on the carriage engages and displaces in return direction an element 88 on the frame in the form of an upright arm. The arm 83 is adjustably settable on the lever by an eccentric device indicated at 89. The arm-element 88, at its lower end, by means of a pinand-slot connection 91, has pivotal support upon a frame bar 90, a spring 92 keeping the element normally raised to the upward limit of the connection 91. The element 88 stands normally in an idle or neutral position seen in Figures 1 and 5 from which it is displaceable rightwardly, as viewed from the front of the machine, by the carriage supported return shut-off element 87, and from which it is displaceable oppositely by a line-end margin stop 95 to lock the type keys. Referring specifically to Figure 5, said neutral position prevails normally in view of the three-armed structure 98 being limitedly spring urged to the position shown, and in view of an arm 96 being spring urged oppositely to a limit afforded 4 by a pin 97. The said arm 96 and the pin 97 have support on the housing 99.

For release of the latch 84 the element 88 operates upon a three-armed structure 98 pivotally carried on a stud 100 provided fast in a housing 99 supported on the framework of the machine. Said arm structure 98 has one arm 101 upreaching for operation by the element 88 and a second arm 1 02 pivotally carrying the latch 84 as at 85. In Figure 5 the latch 84 is under tension of a spring 103, to press against the lug of the arm 83, ready to catch the lever 70 upon its movement to the closed clutch position seen in Figure 6. Thus at operation of lever 70, said latch 84 will catch and hold said arm 83, operated until in the ensuing power return run of the carriage the shut-off element 87 displaces the frame-supported element 88 in return direction, such displacement swinging the three-armed structure 98 to release the latch 84, it being noted that an eccentrically adjustable pin 104 borne on the arm 102 acts on the latch 84 for this purpose. Responsively the lever 70 is restored under action of the spring 69 and the clutch controlling structure 73 moves to normal position, opening the return clutch. At this time, although the carriage is no longer power drawn in return direction, it will be allowed momentarily to proceed until its momentum has dissipated, the carriage feed spring 29 being ultimately effective to draw the carriage in advance direction to a line-start position which may approximately coincide with the position at which the return shut-off occurs. 'The purpose of permitting overtravel of the carriage in its return is to avoid undue shock, noise and strain which would be attendant to abrupt interception of the carriage. It is desirable, however, to have the carriage overtravel a minimum distance, that is, to reverse its direction of movement in the shortest time practically feasible for the required quiet action so that the operator thereupon is enabled to continue typing at the earliest possible moment. Accordingly the displacement of the element 88 in carriage return direction is opposed by means having the effect of decelerating the carriage very rapidly.

Referring particularly to Figures 5 and 7, a spring 105 having'anchorage on the machine frame, biases a bell crank 106 normally against an adjustable abutment 107, there being a link 108 connecting the bell crank to the arm 102 of the three-armed structure 98. The link 10S and the bell crank arm to which it is connected stand normally at an angle to each other, and spring 105 and the bell crank arm to which it is connected are normally very nearly in alignment. Due to the relations just stated, the three-armed structure 98 affords initially very little resistance to the operation of the element 88. This is because the spring 105 is initially extended relatively slowly. As the operation of the three-armed structure proceeds the spring 105 gets extended more rapidly, partly because the bell crank arm 106 to which it is connected swings increasingly more directly in line with the spring 105 and partly because the motion of the bell crank 106 is speeded up by the link 108 having a pull increasingly closer in line to the pivot of the bell crank 106. In case of a long carriage return run, that is in a run wherein the carriage has attained great momentum, the three-armed lever 98 may attain the position seen in' Figure 7 forcing the link 108 virtually into line with the pivot of the bell crank 106. The carriage is thus decelerated to reverse its motion quickly. The arrangement of the parts 106, 108 is such. that the stated deceleration takes place in a very short overrun of the carriage. To enhance the slowing action on the carriage and thereby to minimize the shock, the resilient butter means-comprising the spring 105 is supplemented by resilient buffer means 110 and 111 engageable and strainable by the element 88. The several buffer means are arranged to become successively and accumulatively strained, and further they are of increasing strength in the order they are encountered. The buffers 110 and 111 may be generally U-shaped, springy, elements of steel, having each one leg engageable by the element 88 and another leg attached as at 112 on the tabulator housing 99.

During the return run of the carriage the escapement wheel 36 turns clockwise. The escapement wheel 36 has associated therewith a disk 115 having a lug 116 which at the beginning of each return run of the carriage cams the escapement dog 36 free of the escapement wheel. The said disk 115 is accommodated in a groove attorded by a shouldered disk 118 in conjunction with the underside of the escapement wheel 36, the disk being fastened to the underside of the latter by screws 128. The disk 115 has a split and is slightly distorted as shown in Figure 4, to have a slight friction grip in said groove. A pin 121 fast on the escapement bracket 39, in conjunction with two noses 122, restricts the disk for limited travel with the escapement wheel in either rotative direction. Normally the disk 115 is turned to the clockwise limit so afforded, and the lug 116 stands clear of the escapernent dog 35. Whenever the carriage begins to return, the drag on the disk 115 turns it to the clockwise limit and the lug 116 thereon by traveling over the beveled end of the dog 35 displaces the latter clear of the escapement wheel. During the carriage return the said disk 115 continues tohold the escapement dog 35 in inelfective position. As the return run of the carriage ends, the escapement dog 35 is appropriately controlled so that the car riage ultimately settles in the intended initial recording position. To this end a third arm 123 of the three-armed structure 98 has a downreaching link 124 which, as the carriage overruns its line-start position, will operate a lever 125 to act downwardly on a slide 126 moving it to the position seen in Figure 7. The slide 126 then holds the escapement dog 35 clear of the escapement wheel 36. When then following the overrun the carriage advances to the line-start position under the urge of the feed spring 29, the element 88 and the threearmed lever 98 restore under the influence of the spring 105. The slide 126 has a sliding support on the bracket 39 as at 130, see Figure 1, and at 131 another sliding support on an arm of a tabulating mechanism, not shown, said tabulating mechanism, Whenever operated, being effective to depress said slide 126 to release the escapement dog 35. The slide 126 when acted upon downwardly by the operation of the three-armed lever 93 is arrested at the support 139 but the connection between the link 124 and the lever 125 is flexible in that it comprises a spring 132 which after the slide 126 has moved to the downward limit will yield upon further movement of said threearmed structure. The connection comprising the spring 132 provides at the restoration of the three-armed structure 98 for the restoration of the slide 126 to normal position as the carriage reaches the intended initial recording position, the slide having a spring 133 associated therewith. Consequential to the restoration of said slide 126 the escapement dog 35 urged by a spring 134 moves into position to intercept the escapement wheel 36 by the proper tooth for the arrest of the carriage in the initial typing or recording position.

According to the invention provision is made to in capacitate or disable the typing or other recording instrumentalities for the duration the overrun of the carriage prevails. Incapacitation prevails preferably also prior to the overrun of the carriage during the power return of the carriage. Referring to Figure 1 it will be seen that the machine includes in association with the actuators 64, to the rear and below thereof, a toothed lock slide 135 normally disposed in the position shown so that the actuators 16 at operation of the control keys 22 therefor are adapted to enter freely between the teeth 136 of the said slide, and therefore are connectable with the toothed roll for power operation thereby to drive the type bars 12 against the platen 26 to effect recordings. The slide .is slidably borne on the crossbar 25 of the machine, as at 137, for movement rightwardly to bring the teeth 136 thereon underneath the actuators 16, thereby to lock them against downward operation, that is to incapacitate the keys or controls 22. The lock slide 135 is preferably operated to effective position already when responsive to the depression of the carriage return key 57 the lever 70 moves the clutch closing structure 73 to closed-clutch position. To this end the lever 70 has reaching leftwardly therefrom a push rod 138 which by an adjustable shoulder afforded by a nut 140 is adapted to operate a member 141, the latter having pivotal support upon an upright stud 142 provided on the frame bar 90. The member 141 is operated anti-clockwise and through a flexible connection afforded by a spring 143 actuates the slide 135 to effective position, see Figure 2. Normally the member 141, under the urge of a spring, positions the slide at its leftward limit in accord with Figure l, the member 141 abutting the lug on the slide for this purpose.

When the return shut-off element 87 on the carriage operates the shut-off element 38 on the frame, the threearmed structure 98 is operated as in Figure 7 and causes the release of the latch 84 and in turn the lever '70 restores to open the carriage return clutch 51, 53, 55. At the same time the arm 102 becomes so positioned in respect to a branch 145 of the member 141 that while the overrun of the carriage beyond said initial recording position prevails said member will be held operated, see Fig ures 2 and 7. It will be seen that although at the end of the power return run of the carriage the lever 70 becomes restored by the release of the latch 84, the lock slide 135 nevertheless remains active. All the while effective operation of the type keys 22 is prevented, inasmuch as the actuators 16 are blocked by the slide teeth 36 against movement into motion receiving relation with the power roll '20.

In the event the carriage is returned by hand and thus the member 141 is not operated by the clutch closing lever 70, the three-armed lever 98 nevertheless becomes operated by the overrun of the carriage insofar as in that event the arm 102 glides along a cam face 146 of the branch 1145, displacing the member 141 pivotally to operate saidlock slide 135. As the three-armed lever 98 recovers normal position following the overrun of the carriage, that is as the carriage nears the initial recording position, the arm 102 restores and thus allows the spring to restore the lock slide 135 to the idle, that is, normal position. The recording mechanism comprising the types is then again responsive to the keys 22.

The locking slide 135 is also operable when the carriage reaches a line-end position defined by the aforestated margin stop 95. At such time the line-end defining stop 95 on the carriage displaces the element 88 rightwardly as seen from the rear of the machine in Figure 5, and the motion so given the element 88 is transmitted to a lever 148 that is co-axially carried with the member 141, see Figure 1. Said lever 148 has a lug at the front end to actuate the member 141 and therefore to actuate the slide 135. The actuators 16 then being unresponsive to the keys 22, the operator will know that the line-end margin has been reached. The spring 143 intermediate the member 141 and the slide 135 permits delayed action on the slide in the event an actuator 16 has just been lowered to receive a powerstroke.

The element 88 is adapted to be lowered by the operation of a margin release key, not shown, to permit typing beyond the margin.

Having explained the nature of the objects of the invention and having specifically described a .machine embodying the invention in a preferred form, what is claimed is:

1. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy diiferent recording positions in which said carrier relatively to the recording means is variously disposed 7 for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to step-advance said carriage to successive recording positions beginning from an initial recording position, the carriage being returnable to overrun said initial recording position, a device operable by the overrunning carriage to have control over said step-feeding mechanism so that following the said overrun there will ensue automatically an advance of the carriage to said initial recording position, and means including a control element on the carriage to disable automatically said control means for the duration of the overrun of the carriage and until the carriage arrives at the said initial recording position.

2. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy different recording positions in which said carrier relatively to the recording means is variously disposed for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to step-advance said carriage to successive recording positions beginning from an initial recording position, normally idle power means efiectuatable to return the carriage forcibly and to cause it to overrun said initial recording position, a device operable by the overrunning carriage to have control over said step-feeding mechanism so that following said overrun there will ensue automatically an advance of the carriage to said initial recording position, and means to disable said control means from the time said power means is effectuated and until the carriage after its overrun reaches its initial recording position, said disabling means including carriage-controlled means to hold it active following the overrun of the carriage until the initial recording position is reached.

3. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy different recording positions in which said carrier relatively to the recording means is variously disposed for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of means impositively urging the carriage in an advance direction, a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to cause step-advances of the carriage to successive recording positions beginning from an initial recording position, normally idle power means effectuatable to return the carriage forcibly about to the said initial recording position and allowing it to overrun such position under power of momentum, normally ineffective means to free the carriage totally from the step-feeding mechanism and additionally to disable said control means, and means to cause said freeing and said disabling means to be eifective during the power return run and the subsequent overrun of the carriage and until the carriage arrives at the said initial recording position.

4. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy different recording positions in which said carrier relatively to the recording means is variously disposed for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of means impositively urging the carriage in an advance direction, a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to cause step-advances of the carriage to successive recording positions beginning from an initial recording position, normally idle power means effectuatable to return the carriage in opposition to said urging means approximately to the said initial recording position, the attained momentum of the carriage causing it to'overrun, means to intercept the overrunning carriage softly and comprising a plurality of resilient devices becoming successively and accumulatively strained by the overrun movement of the carriage and thereby efiecting softly and quickly the reversal of the carriage, a device conditioned by the overrun of the carriage to control said step-feeding mechanism to allow automatically the advance of the carriage to said initial recording position, and means including an element on the carriage to disable automatically said control means for the duration of said overrun of the carriage and until the carriage thereafter arrives at the said initial recording position.

5. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy different recording positions in which said carrier relatively to the recording means is variously disposed for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to stepadvance said carriage to successive recording positions beginning from an initial recording position, the carriage being returnable to overrun said initial recording position, an element displaceable by said carriage incidental to its said overrun and substantially until the overrun ceases to exist, means to control said step-feeding mechanism by said element so that an automatic advance of the carriage to said initial recording position will follow said overrun, and means operated by the displacement of said element to disable automatically said selectively operable control means during the overrun of the carriage and pending the arrival thereof in said initial recording position.

6. In a business machine having recording means, a carriage and a record carrier, the carriage adapted to occupy diiferent recording positions in which said carrier relatively to the recording means is variously disposed for a record to receive recordings in different positions, the combination with selectively operable control means to which said recording means is normally responsive, of a step-feeding mechanism normally in control of the carriage and adapted to respond to said control means to step-advance said carriage to successive recording positions beginning from an initial recording position, the carriage being returnable to overrun said initial recording position, an element displaceable from a normal position in either of two directions, means biasing said element in either direction to its normal position, a part on the carriage to operate said element in one of said directions as the carriage in its return overruns the initial recording position, another part on the carriage to operate the said element in the other direction by the advance of the carriage beyond a certain recording position, means to control said step-feeding mechanism by the operation of said element in said one direction so that there will ensue an automatic advance of the carriage to the said initial recording position, and means operated by displacement of said element in either direction from its normal position to disable said selectively operable control means, said control means being automatically enabled again as said element restores to normal position.

7. The combination in a typewriter or the like having a frame, a returnable letter-feeding carriage, means normally urging the carriage in letter-feed direction, a letter-feed escapement normally in control of the carriage, a typing mechanism comprising types and controls to select said types to eifect individual typing operations, means to operate said escapement in accompaniment with each typing operation, and means controlled by the return of the carriage beyond a line-start position to cause the carriage to advance subsequently to said line-start position, of a carriage-carried element adjustable parallel to the carriage to different positions, a frame-carried element operated and restored under control of said carriage-carried element respectively incidental to return travel beyond said line-start position and incidental to advance travel to said line-start position, and means controlled by said frame-carried element to incapacitate said controls substantially for the duration of operation of said frame-carried element.

8. In a typewriter or the like, the combination with a returnable letter-feeding carriage, means normally urging the carriage to advance in letter-feed direction, a letterfeed escapement including a dog normally holding the carriage against advance, a typing mechanism comprising types and controls to select said types to efiect individual typing operations, and means to operate said escapement in accompaniment with each typing operation, of means to power-return the carriage, including a normally open carriage return drive and means operable to close said drive and responsive to the return of the carriage to a certain position to open said drive but allow overtravel of the carriage under force of momentum, means to release said escapement dog for the duration of the return run of the carriage, the said overrun and until the carriage under influence of said urging means nears a line-start position related to said certain position, means to incapacitate said controls by operation of said drive closing means for the duration of the return run of the carriage, and means further to incapacitate said controls for the duration of the overrun of the carriage and until the carriage arrives in said line-start position.

References Cited in the file of this patent UNITED STATES PATENTS 906,600 Anderson Dec. 15, 1908 1,053,065 Ronchetti Feb. 11, 1913 2,232,114 Khalil Feb. 18, 1941 2,258,116 Khalil Oct. 7, 1941 

